Method of casting tetrahedrons



METHOD OF CASTING TETRAI-IEDRONS Filed June 8, 1951 2 sheets-sheet 1 /4aINVENTO'R I 6 Damn. F. SHELDON .l a v I Wrmzss:

Sept. 6,1932. 3, SHELDON 1,875,668

METHOD OF CASTING TETRAHEDRONS Filed June 8. 1931 2 Sheets-Shee 2INVENTOR E Smamw DAN! Patented Sept. 6, 1932 Dim r. sniiLnon, or Losanennns, CALIroman; l, a a

METHOD OF CASTING TE'I RAHEIPRONS Application filed June 8,

Skeleton tetrahedrons for use for the purpose set forth must be massiveand strong and are made of a metallic framework on which concrete ismolded to form the corners i6 and beams or legs.

.1 material and labor. Experience shows this work can be performed at acentral plant or a station where exact materials for the making of samecan be procured and a better grade of concrete be properly cured in theyard; but owing to the great weight and unshippable size of most ofthese complete figures it is impracticable to make them complete at acentral plant.

An object of this invention is to provide a practical skeletontetrahedron adapted for manufacture in separate parts that may betransported independent of each other to the place of use, and to makeprovision whereby such parts may be readily assembled and fasmade intointegral units.

Another object is to provide a precast tetrahedron formed of permanentmaterials, which is adapted to quickly become anchored in the stream bedunder the erosive and depositing action of the water withoutdisintegration, a device which may become displaced without impairingthe stream bank, and to slow down the water sufliciently adj acent tothe bank and bottom to insure the collection of silt and detritusagainst the same and the remainder of the stream being allowedto flow onunimpeded.

Experience in the use has shown in order to prevent the units from beingcarried away,

the end ones or those that are exposed to heavy current action must bestrongly fastened together so as to make a flexible unit of the row offigures that they may readily conform to the irregularitiesof currentaction.

Another object of the invention is to secure maximum strength in acomposite reinforced concrete precast skeleton tetrahedron andparticularly to strengthen the corner pieces,

tened together at the place of use, and thereby and 'dispose -thepartsto maximum advantages of anchoring efficiency.

Other objects, advantages and features of invention may appear from. theaccompanying drawings, the subjoined detailed descripti'on andtheappended claim. l g

I The accompanying drawings illustrate the invention. w 3 5 Figure 1 isaplan view on a small scale of a'stream or river in which is shown aseries of skeleton tetrahedrons placed in a desired positionfrom one ofther iver banksand also shows a cable fastening each tetrahedrontogether to form a flexible row of figures Arrows denote the directionof the river flow.

Fig. 2 is a side view of askeleton' tetrahedron shown embedded iri theriver bottom with thewater flowingin the direction ofthe arrow. r V

'Fig.3 is an enlarged fragmenta'l face view of a precast'leg. i I YFig.- 4 is a side elevation of Fig. 3.

Fig. 5 is a detail plan viewshowing the connection of three legsections.- a i Fig. 6 is an enlarged fragmental detail showing one ofthe bolt connections; I

Fig. 7l'is an enlarged front elevational fragmentaldetail 'view showinganother type of loop used to keep the cable in contact'with a leg of thetetrahedron. v Fig. 8 is a plan view of Fig. 7 r Fig. 9 is a plan Viewof a skeleton'tetrahedron forming a unit constructed in'accoidancewiththis invention; it I Fig. 10 is "a side view of the same on a smallerscale. Y Y a Fig. 11 is a .front view. Fig. ,12 is an enlarged side viewframe of a leg section; 1 l Fig. 13 is an'end vie'w of.Fig.'1'2. Fig. 14is a top'view'of one of the leg sections. T 2- 1 a 7 Fig. 15 is anenlargedsection; on 1ineX1 5 Fig. 16 is- 'a side'view of: Fig. 14:." fFig.1? is a'bo'ttom"=plan view of Fig.116. -(The skeleton tetrahedroniscomposed of six leg sections 1, which are alike, and twelve joints 2,which are alike; {connecting the leg sectionstoeach othen' 7 of thesteel The leg sections 1 are provided with reinforcing rods a, b, 0, dand e having straight bodies 3 and rods a, b and 0 have terminal loopsor bends 4 that project from the faces 5 of the ends of the leg members.The loops at the ends of the leg sections are alike and are adapted andarranged to be juxtaposed to receive the pins 6 which. are preferably inthe form of bolts having a taper end 7 and a slot 8 into which a taperedkey 9 is fitted against a washer 10 to hold the pairs of j ux-- ta osedloops together.

'ie wires 11 are preferably positioned along the frame work of thereinforcement rods to hold the latter in proper adjustment.

The terminal loops are economically made by bending the rod terminals toform a U bend, the base of which will protrude beyond the ends of theleg section and are staggered as shown in Fig. 5, to allow theconstructor to insert the pins 6 through the loops and make them securebefore filling the triangular gap with concrete or other cementitiousmaterial to complete the reinforced joint.

The body of the rod beyond the base of the loop is of sufiicient lengthto be embedded in the body of the leg section as the case may be whenthe same is molded at the place of manufacture.

Referring to Fig. 1 the method shows a row of tetrahedrons placed inposition from one of the river banks, and fastened by a can 12 that maybe anchored at 13'to the ban v The cable 12 is shown slidably fixed tothe front legs of each tetrahedron by the loops 14 andis fastened to theend unit asat 15. This arrangement or method of' fastening eachtetrahedron by a cable to form a flexible row of figures that mayreadily conform to the irregularities of the current flow of the streammay be carriedout in other'forms of construction and there is no limitas. to the number of units or cables or type of loops that may be vusedwithout departing from the spirit of my invention. 'Iclaimr- '7 Y Themethod of producing reinforced concrete tetrahedrons adapted for servicein establishing and maintaining river banks in and with alluvial soildeposits, wherein the tetrahedron sides are angular and of skeletonformation with the skeleton legs arranged to complete the sideconfiguration, said method consisting in precasting the legsindividually with enlarged ends and with reinforcing elements exposed atthe ends of the leg, producing the embryo tetrahedron by assembling therespectivelegs into thetetrahedron form w1th the exposed reinforcingelements at an end of a leg positioned relative to those of an adjacentleg to permit the elements to be secured together to anchor the legsrelatively with the anchor elements exposed, and then completing thetetrahedron by the addition

